Poor neutralization and rapid decay of antibodies to SARS-CoV-2 variants in vaccinated dialysis patients

Patients on dialysis are at risk of severe course of SARS-CoV-2 infection. Understanding the neutralizing activity and coverage of SARS-CoV-2 variants of vaccine-elicited antibodies is required to guide prophylactic and therapeutic COVID-19 interventions in this frail population. By analyzing plasma samples from 130 hemodialysis and 13 peritoneal dialysis patients after two doses of BNT162b2 or mRNA-1273 vaccines, we found that 35% of the patients had low-level or undetectable IgG antibodies to SARS-CoV-2 Spike (S). Neutralizing antibodies against the vaccine-matched SARS-CoV-2 and Delta variant were low or undetectable in 49% and 77% of patients, respectively, and were further reduced against other emerging variants. The fraction of non-responding patients was higher in SARS-CoV-2-naïve hemodialysis patients immunized with BNT162b2 (66%) than those immunized with mRNA-1273 (23%). The reduced neutralizing activity correlated with low antibody avidity. Patients followed up to 7 months after vaccination showed a rapid decay of the antibody response with an average 21- and 10-fold reduction of neutralizing antibodies to vaccine-matched SARS-CoV-2 and Delta variant, which increased the fraction of non-responders to 84% and 90%, respectively. These data indicate that dialysis patients should be prioritized for additional vaccination boosts. Nevertheless, their antibody response to SARS-CoV-2 must be continuously monitored to adopt the best prophylactic and therapeutic strategy.

Poor neutralization and rapid decay of antibodies to SARS-CoV-2 variants in vaccinated dialysis patients

Patients on dialysis are at risk of severe course of SARS-CoV-2 infection. Understanding the neutralizing activity and coverage of SARS-CoV-2 variants of vaccine-elicited antibodies is required to guide prophylactic and therapeutic COVID-19 interventions in this frail population. By analyzing plasma samples from 130 hemodialysis and 13 peritoneal dialysis patients after two doses of BNT162b2 or mRNA-1273 vaccines, we found that 35% of the patients had low-level or undetectable IgG antibodies to SARS-CoV-2 Spike (S). Neutralizing antibodies against the vaccine-matched SARS-CoV-2 and Delta variant were low or undetectable in 49% and 77% of patients, respectively, and were further reduced against other emerging variants. The fraction of non-responding patients was higher in SARS-CoV-2-naïve hemodialysis patients immunized with BNT162b2 (66%) than those immunized with mRNA-1273 (23%). The reduced neutralizing activity correlated with low antibody avidity. Patients followed up to 7 months after vaccination showed a rapid decay of the antibody response with an average 21- and 10-fold reduction of neutralizing antibodies to vaccine-matched SARS-CoV-2 and Delta variant, which increased the fraction of non-responders to 84% and 90%, respectively. These data indicate that dialysis patients should be prioritized for additional vaccination boosts. Nevertheless, their antibody response to SARS-CoV-2 must be continuously monitored to adopt the best prophylactic and therapeutic strategy.

Contribution of Early Failure to Outcome on Peritoneal Dialysis

Background

The technique failure rate on peritoneal dialysis (PD) remains high despite technical progress. There are no data concerning the contribution of early failure to outcome on PD.

Aim

To analyze the importance of early treatment failure in PD and to compare early with late failures with respect to reasons and predictors of risk for failure.

Methods

We performed a retrospective study of all patients admitted for PD from October 1983 to June 2005. The end point was PD failure-free survival. Differences between reasons for failure with respect to early (within 6 months) and late failure were analyzed. Multivariate associations of baseline covariates with early and late failure were investigated.

Results

We included 279 patients. 153 (55%) patients experienced PD failure: 97 (63%) of them had technique failure; 56 (37%) patients died due to non-PD-related causes. 29% ( n = 44) of all PD failures and 40% ( n = 39) of all technique failures occurred within 6 months. Catheter and psychosocial problems contributed more often to early than to late failure, whereas infections, leakages, and hernias contributed equally to early and late failure. Death was the predominant reason for late failure. Female sex was a risk factor for early failure and older age a risk factor for late failure. Higher cholesterol levels were associated with a decreased risk for both early and late failure.

Conclusion

The contribution of early failure to outcome on PD is important, as one third of all PD failures and 40% of all technique failures may occur within the first 6 months, as shown in our study. Due to the retrospective nature and the single-center character, the results cannot be generalized. However, it is important to enhance recognition of patients at high risk for early PD failure prior to initiation of PD, in order to avoid unnecessary surgical interventions and medical complications, and for rational resource allocation.

Reduced Complications during Hemodialysis by Automatic Blood Volume Controlled Ultrafiltration

Background

Intradialytic morbid events (IMEs, mostly hypotension) are frequent complications during hemodialysis (HD). This study investigated whether automatic feedback control via adjustment of the ultrafiltration rate reduces IME frequency.

Methods

In this multi-center cross-over study, 56 hypotension-prone patients were treated both with standard HD (sHD, applying a constant ultrafiltration rate) and HD applying a blood volume controlled ultrafiltration rate (cHD). The relative blood volume (RBV) was continuously monitored. The individual relative blood volume limit (RBVcrit) was determined from the measured RBV during initial sHD. During cHD, the ultrafiltration rate was automatically adjusted to keep the actual RBV above RBVcrit.

Results

In 3,081 HD treatments, slightly fewer IMEs were observed during cHD than during sHD (0.785±0.613 versus 0.695±0.547 per treatment, P=0.144). Less symptomatic events were seen during cHD: -13% for symptomatic hypotension (0.594 versus 0.685 per treatment, P=0.120), and -32% for cramps (0.049 versus 0.072 per treatment, P=0.009). Thirty-one patients with the highest IME rate (IME in at least every second treatment) especially benefited from cHD: 1.185±0.554 versus 0.979±0.543 IME per treatment (P=0.004). The reduction in blood pressure (BP) and the increase in heart rate were lower during the treatments with cHD than with sHD: systolic BP: -18.8±26.7 versus -22.2±28.9 mmHg (P=0.007), diastolic BP: -7.8±14.8 versus -9.1±15.3 mmHg (P=0.064), heart rate: 1.8±10.4 versus 2.3±11.6 per minute (P=0.014). Neither treatment duration nor ultrafiltration volume was significantly different between cHD and sHD.

Conclusion

For cHD, less intradialytic morbid events were observed than for sHD, and pre- to post-dialytic changes in blood pressure and heart rate were less pronounced.

Morbidity and mortality on chronic haemodialysis: a 10-year Swiss single centre analysis

BACKGROUND

Patient survival on chronic haemodialysis varies considerably among different countries and healthcare systems. To date, the survival of Swiss dialysis patients has not been analysed separately.

METHODS

We consecutively enrolled 266 patients entering the chronic haemodialysis program of the University Hospital Basel between 01.01.1995 and 30.06.2006 into a cohort study. Patient survival on chronic haemodialysis was the primary endpoint. Pre-specified sub-group analyses were performed for female and diabetic patients.

RESULTS

Patient age ranged from 15 to 90 years. Seventy-two percent suffered either from coronary artery, peripheral artery or cerebrovascular disease and 34% from diabetes. Sixty-nine (26%) patients underwent kidney transplantation. Transplanted patients were significantly younger (p <0.01) and less likely to suffer from diabetes (p <0.01) and atherosclerotic diseases (coronary, peripheral, cerebrovascular p for all ≤0.01). Median survival was 4.25 years (95%CI 3.66-5.50), with one, three and five year survival rates reaching 88%, 68% and 46%. Survival rates were equal in men and women (p = 0.34), among diabetic and non-diabetic patients (p = 0.41) and among men and women stratified for the presence of diabetes (p = 0.13). Overall, 34% (91/266) patients died during the observational period. Thirty three percent of all deaths were caused by cardiac events, followed by malignant diseases (8%) and infections (7%). In 9% (23/266) dialysis was withdrawn and withdrawal of dialysis contributed to death in 25% (23/91).

CONCLUSION

Survival on chronic haemodialysis treatment in Switzerland compares favourably to international reference values. Dialysis withdrawal and the frequency of kidney transplantation impact long term patient outcome and should be adjusted for when comparing mortality analysis.

Medikamentöse Nicht-Adhärenz – Prädiktive Faktoren und Diagnostik

Gründe für medikamentöse Nicht-Adhärenz sind vielfältig und komplex. Es gibt derzeit keinen etablierten Goldstandard zur Erfassung von Nicht-Adhärenz. Wir stellen mit Nicht-Adhärenz verbundene Faktoren anhand von fünf Adhärenz-Dimensionen und anhand des subjektiven Bewertungsprozesses von Patienten vor. Basierend auf der aktuellen Evidenzlage empfehlen wir folgende zweistufige Adhärenz-Abklärung für die Klinik: 1) routinemäßige Adhärenz-Abklärung anhand des Patienten-Selbstberichts ergänzt mit Hinweisen auf Nicht-Adhärenz aus weiteren Quellen; 2) vertiefte Adhärenz-Abklärung für Patienten mit positivem Hinweis auf Nicht-Adhärenz mittels Gespräch. Die Adhärenz-Abklärung geht dabei zur Adhärenz-Unterstützung über. Adhärenz ist das Ergebnis einer partnerschaftlichen Zusammenarbeit zwischen Patienten und dem Gesundheitspersonal. In komplexen Fällen ist sie als ein, in mehreren Etappen zu erreichendes Fernziel zu betrachten.

Contribution of early failure to outcome on peritoneal dialysis

BACKGROUND

The technique failure rate on peritoneal dialysis (PD) remains high despite technical progress. There are no data concerning the contribution of early failure to outcome on PD.

AIM

To analyze the importance of early treatment failure in PD and to compare early with late failures with respect to reasons and predictors of risk for failure.

METHODS

We performed a retrospective study of all patients admitted for PD from October 1983 to June 2005. The end point was PD failure-free survival. Differences between reasons for failure with respect to early (within 6 months) and late failure were analyzed. Multivariate associations of baseline covariates with early and late failure were investigated.

RESULTS

We included 279 patients. 153 (55%) patients experienced PD failure: 97 (63%) of them had technique failure; 56 (37%) patients died due to non-PD-related causes. 29% (n = 44) of all PD failures and 40% (n = 39) of all technique failures occurred within 6 months. Catheter and psychosocial problems contributed more often to early than to late failure, whereas infections, leakages, and hernias contributed equally to early and late failure. Death was the predominant reason for late failure. Female sex was a risk factor for early failure and older age a risk factor for late failure. Higher cholesterol levels were associated with a decreased risk for both early and late failure.

CONCLUSION

The contribution of early failure to outcome on PD is important, as one third of all PD failures and 40% of all technique failures may occur within the first 6 months, as shown in our study. Due to the retrospective nature and the single-center character, the results cannot be generalized. However, it is important to enhance recognition of patients at high risk for early PD failure prior to initiation of PD, in order to avoid unnecessary surgical interventions and medical complications, and for rational resource allocation.

Pseudotumor of gout in the patella of a kidney transplant recipient

BACKGROUND

A 33-year-old renal transplant recipient presented with painless swelling of the right knee. Physical examination revealed an impressive knee joint effusion with no signs of inflammation. The patient did not remember a recent trauma, but he mentioned a strain 3 years earlier; radiographic findings had been normal at that time. The patient had suffered from end-stage renal disease due to chronic glomerulonephritis and had previously undergone two transplantations. At presentation, his kidney function was stable under treatment with ciclosporin, azathioprine and steroids.

INVESTIGATIONS

Conventional radiography revealed a tumor at the superolateral pole of the right patella. Extensive soft tissue invasion and bone destruction was seen on MRI. A knee arthroscopy with biopsy, performed to aid diagnosis, showed extensive chondrocalcinosis macroscopically; histologically, gouty tophi were found.

DIAGNOSIS

Pseudotumor of gout in the patella.

MANAGEMENT

Uric-acid-lowering therapy with benzbromarone was started immediately after diagnosis. A local arthroscopic debridement of the right knee joint was performed 4 months later, and the patient remained asymptomatic for the next 3 years.

Prevalence and consequences of nonadherence to hemodialysis regimens

Adherence to fluid restrictions and dietary and medication guidelines as well as attendance at prescribed hemodialysis sessions of a hemodialysis regimen are essential for adequate management of end-stage renal disease. A literature review was conducted to determine the prevalence and consequences of nonadherence to the different aspects of a hemodialysis regimen and the methodological obstacles in research on nonadherence. Nonadherence to the prescribed regimen is a common problem in hemodialysis and is associated with increased morbidity and mortality. Research on nonadherence is associated with 2 major obstacles: inconsistencies in definitions and invalid measurement methods. Further research is needed to validate measurement methods and to establish clinically relevant operational definitions of nonadherence.

Prevalence and Consequences of Nonadherence to Hemodialysis Regimens

Adherence to fluid restrictions and dietary and medication guidelines as well as attendance at prescribed hemodialysis sessions of a hemodialysis regimen are essential for adequate management of end-stage renal disease. A literature review was conducted to determine the prevalence and consequences of nonadherence to the different aspects of a hemodialysis regimen and the methodological obstacles in research on nonadherence. Nonadherence to the prescribed regimen is a common problem in hemodialysis and is associated with increased morbidity and mortality. Research on nonadherence is associated with 2 major obstacles: inconsistencies in definitions and invalid measurement methods. Further research is needed to validate measurement methods and to establish clinically relevant operational definitions of nonadherence.

Measurement of PTH Fragments for Assessment of Renal Bone Disease in Hemodialysis Patients

BACKGROUND

Renal bone pathology involves a spectrum from 'high-turnover' to 'low-turnover bone disease' (adynamic bone disease, classical osteomalacia). The diagnosis of the latter usually requires bone biopsy. Inhibitory parathyroid hormone (PTH) fragments may be useful for its noninvasive diagnosis.

METHODS

A cross-sectional study was performed in 54 patients on chronic hemodialysis which involved measurements of intact PTH (iPTH; Nichols assay), total PTH (tPTH; Scantibodies assay), and the cyclase-activating PTH fragment (CAP). The level of cyclase-inactive PTH fragment (CIP) was calculated. At the same time, serum calcium, phosphorus, and alkaline phosphatase levels as well as the current therapy for secondary hyperparathyroidism were recorded. In selected patients, bone radiographs were evaluated for osteitis fibrosa.

RESULTS

A high correlation (r = 0.94) was found between iPTH and tPTH, with the tPTH levels being lower by 30-40%. A similar association was also found for CAP (r = 0.988) and for CIP (r = 0.93). 3 out of the 54 patients had a CAP/CIP ratio of < or =1 which has been associated with adynamic bone disease. A higher CIP ratio was significantly associated with the use of aluminum-hydroxide- and calcium-containing phosphate binders.

CONCLUSIONS

iPTH and tPTH assays are highly correlated. In a general hemodialysis patient population, low-turnover bone disease appears to be rare, when the CAP/CIP ratio is used as a marker. A high CIP value was associated with therapy using aluminum hydroxide, a drug known to carry a risk of adynamic bone disease.

Inaccurate Self-Monitoring of Blood Glucose Readings in Patients on Chronic Ambulatory Peritoneal Dialysis with Icodextrin

Patients on chronic ambulant peritoneal dialysis (CAPD) are increasingly likely to be treated with a new solution of corn starch-derived glucose polymers called icodextrin. This solution involves a very low carbohydrate absorption leading to a better glycemic control in diabetic patients. However these glucose polymers pass to the blood and are metabolized to oligosaccharids which interfere with blood glucose in distinct capillary glucose analyzers leading to overestimation of glycemia. We assessed the accuracy of glucose measurements with the three most commonly used glucose analyzers compared to venous plasma glucose measurement at our institution in 8 patients (4 patients with type 2 diabetes) on CAPD using icodextrin. Glycemia was measured simultaneously in plasma of venous blood using a reference laboratory method and in capillary blood using Accu-Chek sensor (Rotkreuz, Switzerland) (glucose dehydrogenase method), Glucotrend 2 (Rotkreuz, Switzerland) (glucose-dye-oxyreductase method) and Ascensia elite (Zurich, Switzerland) (glucose oxidase method) glucose analyzers. Only glucose readings with Ascensia elite correspond correctly with venous plasma glucose results (+0.3 mmol/l; n. s.), whereas glycemia was significantly overestimated by Accu-Chek sensor (+4.3 mmol/l; p<0.0001) and Glucotrend 2 glucose analyzers (+3.7 mmol/l; p<0.0001). Thus we conclude that distinct glucose analyzers overestimate real blood glucose concentration and are not suitable for monitoring glycemia in patients on CAPD with icodextrin. On the basis of our results, these patients should use glucose analyzers using glucose oxidase methods. All glucose analyzers should be cross-checked with a laboratory reference method before the application in patients on CAPD with icodextrin is recommended.

Lupus Nephritis

Die Lupus Nephritis ist eine schwere Erkrankung und ein wichtiger Organbefall beim Vorliegen eines Systemischen Lupus Erythematodes (SLE). Eine rasche Diagnose mit anschließender Behandlung ist entscheidend, um eine relevante Organschädigung mit erhöhter Morbidität und Mortalität nach Möglichkeit zu verhindern. Diese Übersichtsarbeit gibt einen Einblick über Pathogenese, klinische Manifestationen, das Labor, die Histopathologie und die Therapie der Lupus Nephritis. Neben der Indikation wird auch auf die verschiedenen Möglichkeiten der immunsuppressiven Behandlung eingegangen. Ebenfalls wird ein konkreter Therapievorschlag und die Kontrolle des Therapieerfolges mittels verschiedener Verlaufsparameter beschrieben.

Interpretation of erythropoietin levels in patients with various degrees of renal insufficiency and anemia

BACKGROUND

Chronic renal failure leads to hyporegenerative anemia due to erythropoietin deficiency. The creatinine clearance and hemoglobin levels, at which anemia treatment with recombinant erythropoietin should be started, are unclear. Interpretation of serum erythropoietin levels in the context of renal insufficiency remains controversial and was addressed in this study.

METHODS

Three hundred and ninety-five patients were randomly chosen out of over 5000 consecutive patients investigated by coronary angiography at a single center between 1997 and 2001. Laboratory values and clinical information were prospectively collected in a central registry. Serum samples were frozen before angiography and now used to measure serum erythropoietin levels and evaluate the relationship between erythropoietin and hemoglobin levels in the context of various degrees of renal insufficiency.

RESULTS

The patients with the lowest renal function (creatinine clearance <20 mL/min) had significantly lower hemoglobin levels than the group with normal renal function. However, erythropoietin levels were identical indicating a lower set point for erythropoietin regulation. Above a creatinine clearance of 40 mL/min a significant inverse correlation between erythropoietin and hemoglobin levels was observed and described with the formula erythropoietin [U/L]= 2.5 x (140 - hemoglobin [g/L]) or alternatively Deltaerythropoietin (U/L) =-2.5 xDeltahemoglobin (g/L). Below 40 mL/min no significant correlation was found.

CONCLUSION

A cut-off level for an altered set point of erythropoietin regulation was determined at 40 mL/min creatinine clearance. Above this cut-off hemoglobin negatively regulates erythropoietin. Below the cut-off erythropoietin levels remain stable. Pathophysiologic concepts for this finding and clinical implications in patients with moderate renal failure are discussed.

Characteristics of hypotension-prone haemodialysis patients: is there a critical relative blood volume?

BACKGROUND

Intradialytic morbid events (IME, mostly hypotension) mainly due to ultrafiltration-induced hypovolaemia still are the most frequent complication during haemodialysis (HD). This study was performed to test the hypothesis that there is an individual critical relative blood volume (RBV(crit)) in IME-prone HD patients.

METHODS

In this prospective international multicentre study, 60 IME-prone patients from nine dialysis centres were observed during up to 21 standard HD sessions without trial-specific intervention. The RBV was monitored continuously by an ultrasonic method (BVM; blood volume monitor). Also, the ultrafiltration rate was registered continuously. Blood pressure was measured at regular intervals, and more frequently during IME. All IME and specific therapeutic interventions were noted.

RESULTS

In total, 537 IME, some with more than one symptom, were documented during 585 HD sessions. The occurrence of IME increased up to 10-fold from the start to the end of the HD session. RBV(crit) showed a wide inter-individual range, varying from 71 to 98%. However, the intra-individual RBV limit was relatively stable, with an SD of <5% in three-quarters of the patients. In patients with congestive heart failure, cardiac arrhythmia, advanced age, low ultrafiltration volume and low diastolic blood pressure, higher values of RBV(crit) were observed. While all correlations between RBV(crit) and patient characteristics alone were found to be of weak or medium strength, the combination of diastolic blood pressure, ultrafiltration volume and age resulted in a strong correlation with RBV(crit): the linear equation with these parameters allows an estimation of RBV(crit) in patients not yet monitored with a BVM.

CONCLUSIONS

An individual RBV limit exists for nearly all patients. In most IME-prone patients, these RBV values were stable with only narrow variability, thus making it a useful indicator to mark the individual window of haemodynamic instabilities.

[C-reactive protein and early diagnosis of kidney transplant rejection]

C-reactive protein (CRP), which is known to rise rapidly in the serum after tissue injuries or inflammation, was measured daily after renal transplantation during hospitalization up to day 28 in 45 consecutive patients. In 16 patients who developed neither an infection nor rejection the CRP level normalized within 3 to 5 days. In 7 out of 14 patients with graft rejection the CRP level rose 1 to 3 days before the clinical signs of rejection. 11 patients with overt infection all had a CRP rise. 6 other patients had a CRP rise: in 5 the clinical situation explained this rise but in the sixth no explanation was found. We conclude from our results that periodic measurement of CRP (for example twice a week), even under aggressive immunosuppression, can help in the early diagnosis of graft rejection after renal transplantation. In the event of infection CRP loses its usefulness with respect to graft rejection and the daily measurements have no further point.

[Clinical aspects of staphylococcal endocarditis]

Patients with staphylococcus endocarditis hospitalized at the Cantonal Hospital Lucerne from 1971 to 1988 are reviewed. A total of 50 patients fulfilled the diagnostic criteria (in 60% of the cases the diagnosis was definite, in 26% probable, and in 14% possible). These 50 patients with staphylococcus infection account for 29% of all patients with infective endocarditis seen during this time interval. Staphylococcus endocarditis affected the mitral valve in 48%, the aortic valve in 36% and--unexpectedly often--the tricuspid valve in 30%. In 54% previously normal valves were infected. Diminished host defence (predominantly intravenous drug addiction and diabetes) was a predisposing feature in 52% of the patients. The average duration of symptoms before diagnosis was 11 days, and in patients with right heart endocarditis it was 21 days. In 20% the condition was not diagnosed before autopsy. The clinical picture was relatively nonspecific: 50% of patients had no diagnostic heart murmur and 10% had no fever. The dominant--often misleading--symptoms were due to embolic complications. Two thirds of the cases with right heart endocarditis had pulmonary emboli. In 38% of the patients endocarditis resulted in heart failure. Overall mortality was 51% and correlated with age and the presence of heart failure, uncontrolled infection or cerebral embolism. In contrast to the high mortality in patients with mitral valve infection (61%), only one of the 11 patients with isolated right heart endocarditis died.

Necrotising enterocolitis and neuraminidase-producing bacteria

In 9 out of 26 newborns with necrotising enterocolitis (NEC) exposure of the Thomsen-cryptantigen (T-antigen), probably due to the action of circulating bacterial neuraminidase, was demonstrated on red blood cells. The serological titres seemed to correlate with the clinical course of the disease. Neuraminidase-producing clostridia were isolated in two of the patients. Reaction between the exposed T-antigen and anti-T-agglutinins, normally present in human blood, may lead to difficulties during blood transfusion. This potential transfusion hazard is best avoided by routine T-antigen-tests and by transfusion of packed or washed red blood cells to T-antigen-positive patients.